This work, Belief and Islam, originally was written in Persian under the title I’tiqâd-nâma by Hadrât Mawlânâ Khâlid al-Baghdâdî, a profound ‘âlim of Islam and a specialist in ma’ârif of tasawwuf. Hâji Faydullah Effendi of Kemah, a khalîfa of great walî Mavlânâ Mahmûd Sâhib, the brother of the author, translated the book into Turkish and named it Farâid-ul-fawâid which was printed in Istanbul in 1312 A.H.[1894]. Our bookstore had it translated again from the Persian original into Turkish and, some explanations and three chapters, published it with the title Imân ve Islâm in 1966. German, French and Arabic versions are also published by our bookstore. This book, explains five fundamentals of Islam, six fundamentals of îmân and the contemporary information about the matter and refutes those who are against Islam and those who are lâ-madbhabî.